1. Field of the Invention
The present invention relates to microwave ovens, and particularly an improved control system and operation method of a microwave oven which includes a microcomputer and operates according to a cooking program stored in a memory.
2. Description of the Related Art
With enlargement of heating functions of a microwave oven, practicable cooking methods have been improved and the number of available menus also has been increased. The enlargement of heating functions includes, more specifically, introduction of a heater as heating means and use of an inverter power supply as a power source.
Utilization of such functions under sequence control by a microcomputer has brought forth heating cooking methods such as grill heating, oven heating, so-called composite heating (in which the microwave heating and the heater heating are alternately performed), and simultaneous heating (in which the microwave output and the heater output are performed according to a predetermined ratio).
With the expansion of the cooking menus, the microwave cooking, the heater cooking, the composite heating cooking, the simultaneous heating cooking and the like have been applied to a large number of ovens utilizing microcomputers and sensor devices, to implement the automation of cooking.
For facilitating use of automated heating cooking methods as described above by users, menu keys for selection of various kind cooking programs and so forth are provided on a cooking portion control cooking which is referred to as a control unit of a common microwave oven.
FIG. 1 is an external view of a conventional microwave oven. Referring to FIG. 1, the microwave oven includes an outer case cabinet 101, an oven door 102, an oven tray 103, a roller stay 104 and a control unit 105a.
FIG. 2 is an enlarged view of a panel portion of control unit 105a. The panel portion includes a display 106, first menu keys 107, a cancel key 108, a heating switch 109, second menu keys 110, heating mode selecting keys 111 and a timer knob 112.
The heating mode selecting key 111 and the timer knob 112 are provided for manually setting cooking programs of menus which cannot be covered by first menu keys 107 and second menu keys 110.
In an operation portion of control unit 105a, as shown in FIG. 3, outlines of the menu keys or names thereof are printed. Also, it includes an overlay 113 having contacts on the backside, a circuit board 116 in which input switches are provided, a membrane sheet 114 for securing contact between each contact provided in overlay 113 and a contact of a corresponding input switch on circuit board 116 when a predetermined position in overlay 113 is depressed, and a spacer 115.
In a conventional microwave oven in which the heating cooking is automated, a plurality of menu keys 107, 110 are provided for selecting cooking programs in a limited space on control unit 105a. Each of menu keys 107 and 110 is assigned to a particular program. Accordingly, limited by the operability of menu keys and the visual recognizability of menu names, it is impossible to provide more than a certain number of menu keys.
If the number of menu keys is increased as much as possible in the limited space on control unit 105a, the number of unnecessary menu keys for a user in each selection increases. Accordingly, a problem is that it is troublesome to find out one desired menu key in a large number of menu keys provided.
In order to solve such a problem, a microwave oven shown in FIG. 4 is disclosed in Japanese Patent Application No. 63-274239. The gist of the application is to display in a "time divisional" manner with video information the layout or menu names of menu keys 107, 110 provided in a control unit 105a which has been introduced in a conventional microwave oven. The application thus has an object of overcoming the problem of the menu key arrangement on control unit 105a of a conventional microwave oven.
Referring to FIG. 4, the microwave oven includes an outer case cabinet 101 having an oven cavity 117, an oven door 102, a roller stay 104, a heating element 118 and a control unit 105b.
FIG. 5 is an enlarged view of a panel portion of control unit 105b. The panel portion includes a display 119, menu name displays 120, menu selecting switches 121, an operation mode selecting switch 122 and an operation mode name display 123. Display 119, menu name displays 120 and operation mode name display 123 are formed of color liquid crystal displays.
The character information and the video information outputted to display 119, menu name displays 120, operation mode name display 123 are recorded in a so-called IC (Integrated Circuit) card or a so-called RAM (Random Access Memory) pack, an external storing means which will be described later. However, information of the operation mode names outputted to operation mode name display 123 (e.g., character strings such as "CLOCK", "MICRO", "GRILL" and "READY") is stored in an operation controlling ROM (Read-Only Memory not shown) provided in control unit 105b.
FIG. 6 is a schematic diagram illustrating external appearances of an IC card 124a or a RAM pack 124b each of which is external storing means and storage structure of a main memory, which store various kinds of cooking information to be stored in a main memory 12 (including RAM) provided in control unit 105b.
Such kinds of information recited below are stored in IC card 124a or RAM pack 124b, and are stored in corresponding areas in main memory 12.
(1) Contents information ... stored in a data area 125a. This is information for displaying stored contents of main memory 12 in display 119.
(2) Cooking program . . . stored in an area 125b.
(3) Menu video data . . . stored in an area 125c. The data is video information indicative of appearance of a selected dish to be displayed in display 119.
(4) Menu name data . . . stored in an area 125d. It is video information of a menu name or color illustration for having a user recognize a menu name to be displayed in menu name display 120.
In the data areas of IC card 124a or RAM pack 124b, that is, in the data areas of main memory 12, various cooking information such as cooking programs, menu video data, menu name data are classified and stored for each heating cooking method (the microwave heating, the grill heating and the like).
Referring to FIGS. 4-7, the transition and operation of display in control unit 105bin the microwave oven will be described in the following. Every time operation mode selecting switch 122 is depressed, the operation modes change in a predetermined order (FIG. 7(a) .fwdarw.(b).fwdarw.(c).fwdarw.(d).fwdarw.(e)). When one cycle of menus is finished, the operation mode returns to the initial operation mode (FIG. 7 (e).fwdarw.(a)).
The operation modes include such modes as recited below.
(1) Clock display mode (FIG. 7 (a))
At the time of power-up of control unit 105b, or when the main body of the microwave oven is not operating for cooking, a time display mode is effected. An example of the operation mode display at that time is "CLOCK".
(2) Microwave cooking mode (FIG. 7 (b))
During the heating more, oscillation of microwave generating means such as a magnetron effects heating. A display example of a mode title in this case is "MICRO". In this operation mode, in menu name displays 120, names of menus to be subjected to the microwave cooking (or with corresponding illustrations of the menus) are displayed. In FIG. 7(b), the names of menus are displayed as "M - 1", "M - 2", "M - 3".
(3) Grill cooking mode (FIG. 7 (c))
During heating mode, heating is effected by 118. An example of the operation mode display in this case is "GRILL". In this operation mode, names of menus for the grill cooking are displayed in menu name displays 120. In FIG. 7 (c), the names of menus are shown as "G - 1", "G - 2", "G - 3".
Three operation modes have been described above. Upon depression of menu selecting switch 121 in each operation mode, the display further changes. For example, FIG. 7 (d) illustrates the appearance of control unit 105b when a menu selecting switch 121 corresponding to the menu name "G - 3" is depressed. An image showing the appearance of the dish corresponding to menu G - 3 is displayed in display 119.
FIG. 7 (e) shows control unit 105b when menu selecting switch 121 for the menu G - 3 is depressed once again in the state indicated in FIG. 7 (d). The names of menus outputted to menu name display 120 in FIG. 7 (d) are erased except the selected menu G - 3. Display 119 displays a message indicating that the menu G - 3 is selected. The message "READY" indicative of finish of a menu selecting operation is outputted to operation mode name display 123.
As clearly seen from the above description, upon depression of operation selecting switch 122, operation modes are switched. Furthermore, by changing the names of menus outputted to menu name displays 120 correspondingly, it is implemented to display the menu key layout in a "time divisional" manner.
As clearly seen from the above description, the microwave oven shown in FIGS. 4-6 solves the problems of the conventional microwave oven of commercial model shown in FIGS. 1-3. That is, the operability of menu keys and limited space on a panel of control unit 105b are maintained while it is possible to use as many cooking programs as possible. Measures taken for solving the problems are to store necessary various kinds of cooking information in an external storage means such as an IC card, thereby enabling exchange of information to be stored in a main memory of a control unit whenever desired, and to switch display contents corresponding to the operation with a menu name display portion formed of a liquid crystal display.
Such measures make it possible to use the developed programs as possible while keeping the high operability of the menu keys within the limitation of heating hardwares. As an image of an appearance of a selected dish is displayed on a color liquid crystal display, confirmation of the selected result is also facilitated.
Furthermore, as a result, the following are enabled. It is assumed that a user has not selected his desired menu yet. The user can depress some menu selecting switches in this case to compare and evaluate images of completed dishes outputted. As a result of the evaluation, a menu which is determined to be the most preferable can be selected finally. The selection is made on the basis of a subjective reference of the user obtained by comparing appetites inspired by the images of menus.
Besides such subjective reference as described above, is it envisioned to enable selection of menus with more objective reference. FIGS. 8 and 9 illustrate a microwave oven capable of counting the number of use of cooking programs every time cooking is performed using the microwave oven and storing the number of times in a memory. In the microwave oven, a user can make the number of use of cooking programs displayed if need be. The user thus can check the latest number of use of respective cooking programs for menus. Such a microwave oven is for business use, which is mainly used in so-called "fast food" shops. This kind of microwave oven is described in Japanese Utility Model Laying-Open No. 62-19501, for example.
FIG. 8 illustrates an operation panel portion of a control device in the above-described microwave oven for business use. Referring to FIG. 8, the operation panel includes a display 151 for outputting information of a selected cooking program, dedicated menu keys 152 for specifically addressing cooking programs stored in a memory corresponding to each menu, a heating start key 153, an attachment 157 to the main body of a control device for memory modules 156a, 156b such as a RAM pack in which cooking programs are stored, a count number call key 158 for inputting an instruction for reading the number of use for each dedicated menu key 152 (the number of use of cooking programs) from a memory and outputting it to display 151, a cooking program input key (MENU ENTRY) 159 for instructing transfer (load) of cooking programs stored in memory modules 156a, 156b to a main memory provided inside responsive to an instruction of a microcomputer provided in the control device, and a program code output key 160 for outputting to display 151 a program code N3 of a cooking program stored in an address of a main memory corresponding to each dedicated menu key 152.
Program code output key 160 is for use when the user checks if the contents of a cooking program and a menu name written in each dedicated menu key 152 correctly correspond to each other. As to the attachment 157 of memory modules 156a, 156b, in the figure, the access panel which is opened and closed when attaching and detaching a memory module is shown.
In FIG. 8, an example is illustrated in which display 151 makes a display meaning that the code N3 of a cooking program stored in an address corresponding to No. 4 of dedicated menu key 152 in the main memory is "111".
FIG. 9 is a block diagram of this microwave oven. In FIG. 9, the microwave oven is displayed divided into output means, input means, control means, internal storing means and external storing means from left to right.
Input means includes dedicated menu keys 152 and three kinds of operation keys (COUNT CALL key 158, MENU CALL key 160, MENU ENTRY key 159).
Output means includes a display 151. Corresponding display is made in the display 151 when an operation key is operated.
Control means includes a microcomputer having a CPU (Central Processing Unit), an operation control ROM, and an input/output interface (I/O).
Storing means includes a RAM. The RAM is referred to as a main memory in order to distinguish it from external storing means (memory module) described later.
The RAM shown in the figure stores information indicative that the number N2 of use of a cooking program (P) of a menu assigned to No. 1 of dedicated menu keys 152 (in the figure "standard hamburger") is fifteen times and the program code N3 thereof is "111".
When a new cooking program is stored in the RAM from the ROM module 156a which is one example of a memory module, as shown in FIG. 9, a cooking program of cooking program code 211 is stored in address N1 in the main memory assigned to No. 1 dedicated menu keys 152, a cooking program of program code 221 is stored in the second one, and the cooking program of the program code 231 is stored in the third one.
In the main memory, corresponding to the number of dedicated menu keys 152, ten addresses N1-N10 are prepared, for example. For each address, a location for storage of the number of use N2, a location for storage of the cooking program code N3, and a location for storage of cooking program P are prepared.
The external storage means is a memory module, which includes a RAM pack or ROM modules 156a, 156b and so forth, for example.
Information stored in each location except the number of use N2 is supplied from external storing means such as ROM module 156a, 156b or the like.
Although not shown in FIG. 9, at the time when a drive signal is sent to an electronic buzzer for producing a cooking finish informing signal produced when the cooking operation of the microwave oven main body by the cooking program P is finished, a signal is transmitted to a corresponding address of a memory of cooking programs the number N2 of use is incremented by 1.
The main features of a function of counting the number of use of cooking programs in a microwave oven for business purpose having such structure as described above are:
(1) The operation for selecting a cooking program of a desired menu in a plurality of prepared menus can be made by selecting a dedicated menu key 152 specifically assigned to each menu and depressing the key. A cooking program stored in an address of a memory corresponding to the selected menu is thus read out.
(2) The number of use of each cooking program is re-written and stored at the time when an instruction indicative of output of a cooking finish informing signal is executed.
(3) The counted result can be checked whenever the user desires. The check is conducted independently of cooking by the menu selection. The operation for the check includes an operation of depressing a count number call key (COUNT CALL key) 158 and an operation of depressing a corresponding dedicated menu key 152 for specifying a cooking program which is an objective of the calling. As a result of the checking, a number of the specified menu key and the number of use thereof are outputted to display 151.
(4) The above-described checking operation is an operation required for checking the number of use of a single cooking program. When checking a plurality of programs, the above-described checking operation is repeated for a desired number of times.
(5) The data outputted as a result of the operation of checking is the unprocessed number of times of use for each individual cooking program. It is left to the user himself how to interpret the data and what to do on the basis of the interpretation.
The microwave oven described in the second place has the following problems. In the microwave oven, an image of appearance of a dish is outputted in display 119 (FIG. 5). It enables a method of use in which a user selects a desired menu after seeing the appearance image. As described above, the selection is based on the subjective reference of the user.
On the other hand, a main user of a microwave oven (a housewife, for example) basically considers information related to favorite dishes of family members, nutritive condition, foods stored in a refrigerator, and various dishes introduced in TV cooking programs and the like.
However, it appears that in practical use by most of users, the menus are selected strongly reflecting favorites of the user rather than the above-identified various elements It is recognized that this often happens in the case of a so-called "poor cook" or users who cannot take enough time for preparing dishes because of some reason.
Especially, it seems that when at a loss about the menu, most of the users select menus mainly on the basis of their own favorites. Here exists a possibility of occurrence of unbalanced menu selection.
Under such circumstances, if a microwave oven is used in which the menu selection is enabled through an effect of inspiring appetite with video information of a completed dish, it is possible that the unbalanced menu selection may be greatly amplified. Accordingly, if a large number of cooking programs are availably prepared in external storing means, it is highly possible that a lot of programs are not used.
However, in any of the above-described conventional microwave ovens, it is very difficult to use all of the prepared cooking programs uniformly. That is, it is extremely difficult to equally use prepared cooking programs. It is also difficult to purchase an optional external medium at an appropriate time for cooking programs of new menus.